package com.thtk;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.*;

import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;


import java.io.IOException;
import java.util.Iterator;
import java.util.StringTokenizer;


/**
 * Created by guop on 2018/10/22.
 */
public class WordCount {

//    public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
//        private final static IntWritable one = new IntWritable(1);
//        private Text word = new Text();
//
//        public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
//            String line = value.toString();
//            StringTokenizer tokenizer = new StringTokenizer(line);
//            while (tokenizer.hasMoreTokens()) {
//                word.set(tokenizer.nextToken());
//                context.write(word,one);
//            }
//        }
//    }
//
//    public static class Reduce extends Reducer<Text,IntWritable,Text,IntWritable>{
//        public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
//            int sum = 0;
//            for (IntWritable val : values){
//                sum += val.get();
//            }
//            context.write(key, new IntWritable(sum));
//        }
//    }
//
//    public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
//
//        Configuration conf = new Configuration() ;
//
//        Job job = new Job(conf, "wordcount");
//
//        job.setOutputKeyClass(Text.class);
//        job.setOutputValueClass(IntWritable.class);
//
//        job.setMapperClass(Map.class);
//        job.setReducerClass(Reduce.class);
//
//        job.setInputFormatClass(TextInputFormat.class);
//        job.setOutputFormatClass(TextOutputFormat.class);
//
//        FileInputFormat.addInputPath(job,new Path(args[0]));
//        FileOutputFormat.setOutputPath(job,new Path(args[1]));
//
//        job.waitForCompletion(true);
//    }
    public static class MyMapper extends Mapper<Object, Text, Text, IntWritable>{
    private final static IntWritable one = new IntWritable(1);
    private Text name= new Text();

    public void map(Object key, Text value, Context context) throws IOException, InterruptedException {
        int idx = value.toString().indexOf(" ");
        if (idx > 0) {
//            String e = value.toString().substring(0, idx);
//            name.set(e);
//            context.write(name, one);
            String line = value.toString();
            StringTokenizer tokenizer = new StringTokenizer(line);
            while (tokenizer.hasMoreTokens()) {
                name.set(tokenizer.nextToken());
                context.write(name,one);
            }
        }
    }
}

    public static class MyReducer extends Reducer<Text,IntWritable,Text,IntWritable> {
        private IntWritable result = new IntWritable();

        public void reduce(Text key, Iterable<IntWritable> values, Context context) throws IOException, InterruptedException {
            int sum = 0;
            for (IntWritable val : values) {
                sum += val.get();
            }
            result.set(sum);
            context.write(key, result);
        }
    }

    public static void main(String[] args) throws Exception {
        Configuration conf = new Configuration();
        String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
        if (otherArgs.length < 2) {
            System.err.println("Usage: NameCount <in> <out>");
            System.exit(2);
        }
        Job job = Job.getInstance(conf, "name count");
        job.setJarByClass(WordCount.class);
        job.setMapperClass(MyMapper.class);
        job.setCombinerClass(MyReducer.class);
        job.setReducerClass(MyReducer.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
        FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
        System.exit(job.waitForCompletion(true) ? 0 : 1);
    }
}
